1. Field of the Invention
The present invention relates generally to an apparatus and a method for an Automatic Retransmission reQuest (ARQ) in a wireless communication system, and more particularly, to an apparatus and a method for sending a control message for the ARQ in a multihop relay wireless communication system.
2. Description of the Related Art
In a wireless communication system, specific data may be corrupted according to a channel condition of a radio resource of the data. Error controlling and correcting methods largely include an Automatic Retransmission reQuest (ARQ) and a Forward Error Check (FEC). According to the ARQ, a receiver requests a transmitter to retransmit the corrupted data. The FEC scheme corrects errors in the compromised data at the receiver.
When the wireless communication system adopts the ARQ scheme, the receiver checks for errors by decoding the received packets. When the received packets are free from error, the receiver sends an Acknowledgement (ACK) message to the transmitter.
When errors are detected in the received packets, the receiver sends a Negative ACK (NACK) message to the transmitter.
Upon receiving the ACK message from the receiver, the transmitter transmits new packets. Upon receiving the NACK message from the receiver, the transmitter retransmits the previous packets to the receiver.
Recently, the wireless communication system provides a relay service using a relay station to provide a better radio channel to a mobile station, which travels in a cell boundary or in a shadow area. That is, the wireless relay communication system can provide a better radio channel between a base station and a mobile station by relaying data between the base station and the mobile station using the relay station.
Thus, the wireless relay communication system requires an ARQ method using the relay station.